SUCCESSION AMONG ROCKS. 277 



On the continent therefore, the red marl is followed 

 by a limestone series called the muschelkalkstein ; 

 though this is sometimes wanting even there, as it 

 appears entirely to be in England. To this succeeds, 

 in the same countries, a sandstone series, the quader- 

 sandstein, sometimes equally deficient, and wanting 

 also in England. That series of limestone and clay 

 or shale, called Lias, is the next ; and this seems to 

 be very widely diffused throughout Europe in general, 

 though it is said not to exist to the south of the Alps. 

 I must also here add, that a new deposit of the qua- 

 dersandstein is said, in some places, to be interposed 

 between the lias and the next class in order, the 

 Oolithe. 



This most extensive group of strata is named from 

 the character of some of the limestones which it con- 

 tains; but the student will commit a great error who 

 considers it as an oolithic limestone, or even as a mere 

 calcareous series. It is an immense group of various 

 strata, of a wide sweep ; including, in many places, a 

 great number of limestone beds of very various cha- 

 racters, of which many are far asunder, and separated 

 by conspicuous deposits of other substances. That it 

 is less likely to be absent than some other of the 

 deposits here named, is a natural consequence of an 

 arrangement so inclusive. 



What follows next in order above, is the sandstone 

 called the ferruginous sand in England, succeeded by 

 the more general Green sand, which is also a complex 

 class of substances, though the prevailing part is 

 arenaceous. Lastly comes the Chalk, a limestone of 

 a peculiar character, considerably definite, though 

 including different varieties and substances, and termi- 

 nating what are considered the secondary strata. For 



